Speed-indicator.



F. W. WOOD.

SPEED INDICATOR.

APPLICATION FILED FEB. 5,1909. 960,762. I v Patented June 7,1910.

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SPEED INDICATOR.

APPLICATION IILED I'EB.5,1909.

- 960,762. Patented June 7,1910.

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960,762. Patented June 7, 1910.

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4a 1 g3 .26 I v W Q .42 a 19 2 J flf /A\ \L\\1.\ \\\\\\\\\\\l\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ nventor Frank Ill. Wand, xihwmo I UNITED STATES PATENT OFFICE.

FRANK w. woon, or NEWPORT NEWS, VIRGINIA, ASSIGNOR '10 CHARLES'CORY & son, or NEW YORK, N. Y.

SPEED-INDICATOR.

Specification of Letters Patent.

Patented June '7, 1910.

Application filed February 5, 1909. Serial No. 476,269.

in connection with prime movers, such as.

engines, in order to determine the speed at which they shall run.

The primary object of the invention is to provide a device of this character having meansfor connection with a rotating, part of the engine or other machine, the speed of which is to be measured, and capable of being set vso as to indicate to the observer when the engine has reached a required or predetermined speed. i

A further object of the invention is to provide a device of this character which shall be com act in' its construction, and positive and e cient in operation, and which shall be capable of withstanding the. wear and tear to which such apparatus will ordinarily be subjected.

\Vith the above and other objects in view, my invention consists in the construction and arrangement of parts hereinafter described and illustrated in the accompanying drawings, in which,

Figure 1 is a front elevation of my improved indicator complete as itappears in use. Fig. 2 is a side elevation thereof. Fig. 3 is a front view of the-mechanism'partly in elevation and partly in section on the line 33 of Fig. 4. Fig. 4 is a transverse section on the line 4,4 of Fig. 3 looking in the direction of thc arrow. Fig. 5 is a plan view of the mechanism contained in the lower part. of the casing. Fig. '6 is a fragmentary side elevation of the same parts with the wall of the casin removed.

Referring to the drawings in detail my improved indicator comprises a rectangular casing '1, the upper part of the front wall whereof is hinged as at 3, constituting a door 2. through which access may be had to the interior of the upper part of the casing.

- The door is normally held closed by means of latches 4. The casing comprises two compartments separated by a floor 1, and n the front wall of the lower compartment is set a glass window 5 through which may .be seen a dial 6 having thereon a graduated scale. In the upper compartment of the casing is located a small constant speed electric motor 7 of any well known type. Also mounted in this upper compartment is a rheostat 8 for controlling the speed of the motor, operated by means of a shaft 9 extending through the casing and carrying at its outer end a hand wheel 10. A second hand wheel 11 is preferably mounted con.- centric with the wheel 10 and controls a reversing switch 12, which may be of any well known construction. Indicia associated with the wheel 11 on the outside of the casing serve to show to the operator whether the switch 12 is set to produce forward or backward rotation of the motor or whether it is at the stop position.

A worm 13 is secured to one end of the motor shaft and meshes with a worm wheel 14 mounted at the upper end of a shaft 15 which extends down through the casing and is journaled in bearings 16 and 17. To this shaft-15 is also attached a worm 18 in the lower compartment of the casing, which worm mesheswith a large worm wheel 19, mounted on a sleeve 20 which in turn is journaled on a second sleeve attached to a 24* at each end. To the front end of the sleeve 20 is secured a pointer 21, which I shall designate as the constant pointer. concentrically mounted with the pointer 21 isa second pointer 22, which I shall hereinafter refer to as the speed pointer and which is mounted at the forward end of a shaft 23 which is supported by means of terial, such as aluminum. The disk 26 has an annular hub 26 in which is seated a coil spring 27. One end of this spring bears against the disk, while the other end is seated a ainst a ring which is supported on ball bearings 28 carried by the cross-bar 24.

The effect of the spring 27 is therefore to constantly urge the disk 26 in a direction away from the cross-bar 24, the disk being splined on the shaft 23, and the ball bearings 28 preventing any undue friction.

A shaft 29 extends through the casing preferably at right angles to the shaft 15 and is journaled in bearings 29 in each wall of the casing, and splined upon this shaft is a small friction wheel 30 made of rawhide or other suitable material. The parts are so arranged that the spring 27 serves to normally urge the face of the disk 26 into contact with the periphery of this wheel. The shaft 29 projects through the wall of the casing and carries suitable gearing (not shown) serving to connect the same with the main shaft of the engine or other machine, the speed of which is to be indicated. In the embodiment shown this gearing preferably has a ratio of 20 to 1 so that the shaft 29 makes only one revolution to 20 of the engine shaft. This, however, is a mere matter of convenience and other ratios may be employed, as desired. As above stated, the wheel 30 is secured to the shaft 29 so as to revolve therewith but is capable of free longitudinal movement thereon. In order to move the wheel 30 longitudinally of the shaft 29 and thus vary its radial distance from the center of the disk 26 I provide a bracket 30 engaging said wheel on each side thereof, and carried by a screwthreaded shaft 31 extending transversely across the casing, and journaled in bearings at each end thereof. Also extending across the casing near the front thereof is another shaft 32 mounted in bearings 33, and carrying near its middle a worm 34. This worm meshes with a worm wheel 35 mounted on a sleeve 36 which turns freely upon the sleeve 20. To the worm wheel 35 is secured one end of a third pointer 37 the other end of which extends up and over the edge of the dial-6 and is bent around the same, as clearly shown in Fig. 4. This pointer will be referred to as the rate pointer. The dial is supported by means of brackets 38 and 40 secured together by means of bolts or rivets passing through spacing sleeves 39. The dial is attached to the bracket 39 secured to the bottom ofthe casing 1 in order to prevent its rotation.

In order to impart rotation to the pointer 37 and to the shaft 31 I provide a hand wheel 41 mounted on a stud shaft 42 at one end of the casing. To this stud shaft is secured a pinion 43. Meshing with this pinion 43 on each side thereof are gears 44 and 45 mounted rigidly on the shafts 31 and 32, respectively. It will thus be seen that by turning'the hand wheel 41 the shaft 31 may be turned so as to cause the bracket carrying the'wheel 30 to travel longitudinally of the shaft 29, and at the same time rotation is imparted to the shaft 32 which by means of the worm gear 35 moves the pointer 37 over the dial.

The method of operation will now be described.

The motor 7 is preferably one which runs at say 3,000 R. P. M., and by means of the worm gears described, its speed is so reduced that the worm wheel 19 and consequently the attached pointer 21 will be driven at one B. P. M. Therefore, whenever the motor is running the pointer 21 constantly travels at a uniform rate around the dial making one revolution per minute. Assume for example that it is desired to run the engine at 100 R. P. M. By means of the hand-wheel 41 the rate pointer 37 is first moved over the scale until it stands over thegraduation mark 100. At the same time that the pointer is moved to this position the wheel 30 will, by means of the bracket 30 and second shaft 31, be moved along the shaft 29 to a definite position corresponding to the speed 100 R. P. M. \Vhile the pointer 21 is being driven by the motor 7 the pointer 22 is being driven by the engine by means of the shaft 29, wheel 30, disk 26 and shaft 23. After setting the rate pointer to the desired figure, the engine is then speeded up until the two pointers 21 and 22 revolve in unison, that is they go around absolutely together, both making one B. 'P. M. When this condition is reached the engine will be making exactly 100 R. P. M. This is due to the fact that in turning the hand Wheel so as to bring the rate pointer to the desired scale division the friction wheel 30 was moved to such a position relative to the disk 26 that the speed ratio between these parts results in 100 revolutions of the engine causing just. one revolution of the pointer 22.

It will be observed that the process of determining the speed of the engine involves an operation similar to that of synchronizing. That is I provide a pointer'driven at constant speed, set the device for a predetermined ratio and then speed the engine up until the two pointers 21 and 22 are in synchronism. Any variation in the speed of the engine, after this condition has been brought about, will immediately result in a divergence or separation of the two pointers. As long as the speed of the engine is constant or uniform the two pointers will stay together or, at least, they will preserve the same angular relation.

Not only is it possible for me by the use of my improved indicator to set'the speed of the engine or other variable speed device to any value I desire, as described in the preceding paragraph, but I may with equal facility determine at what speed such device is running. To do this the operation is simply the reverse of the one just described.

Instead of speedin the engine up until the two pointers 21 and 22 are in synchronism I turn the wheel 41, moving the pinion 30 along the face of disk 26 until the pointers 21 and 22 are in synchronism and the indication of the pointer 37 on the dial 6 is the speed of thetengine. The principal of operation is, of course, the same as in the preceding instance.

It will thus be seen that I have provided a device which 'can be set for any desired speed, and which enables the operator to determine accurately when the engine reaches this speed and whether or not the speed is maintained constant, and it. is thought that the numerous advantages of my invention will be readily appreciated by those skilled in the art.

What I claim is:

1. In a speed indicator, a shaft drivenat constant speed, and means for driving the same, a pointer mounted thereon, a second shaft driven at variable speed, and means for driving the same connected to a device the speed of which it is desired to determine, a third shaft concentric with the first and a pointer thereon in a plane parallel and adjacent to the plane of the first pointer, indicating means mounted in a plane parallel and adjacent to the planes of the first two pointers, variable speed gearing between the second shaft and the pointer on the third shaft, means for shifting said gearing to vary the speed of the pointer on the third shaft, and connections from said means to said indicating means for indicating the speed of the second shaft.

2. In a speed indicator a shaft driven at constant speed and means for driving the same, a polnter thereon, a disk friction gear mounted concentric with and adjacent to the pointer, a second pointer in a plane adjacent the plane of the first-named pointer, means connecting said second pointer to said disk, a second shaft driven at variable speed by the device whose speed is to be determined, a

friction wheel mounted on and adjustable along said second shaft and in engagement with the face of said disk, an indicating )ointer mounted in a plane parallel and ad- ]acent to the planes of the first named pointers, means for moving said friction wheel along the second shaft, and means connecting the indicating pointer with said means for moving the friction wheel along the second shaft for the purpose of indicating the speed of the said second shaft.

3. In a speed indicator a shaft driven at constant speed and means for driving it, a pointer thereon, a second shaft concentric with the first, a friction disk mounted on said second shaft, a pointer also mounted on said second shaft in a posit-ion to be viewed simultaneously with the first pointer, a third shaft revolving at a variable speed, a variable speed gearing between said third shaft and said friction disk, means for changing the said gearing to vary the speed of the said disk, a third pointer mounted on one of'the shafts, a dial over which said pointer is adapted to move, and connections betweenthe means for changing the gearing between the third shaft and the friction disk, and the pointer cooperating with the dial, for causing the last-named pointer to indicate the speed of said third shaft.

4. In a speed indicator a shaft driven at constant speed, and means for driving it, a pointer thereon, a second shaft concentric with the first, a friction disk and a pointer mounted thereon in a position to be viewed simultaneously with the first pointer, a third shaft driven at variable speed by the device whose speed is to be determined, a friction wheel carried by and adjustable alon said third shaft and engaging the face of saidfriction disk, means for yieldingly pressing said friction disk against said friction wheel, means for moving said friction wheel along said third shaft, and means for indicating extent of such movement. v

5. In a speed indicator, an element 'driven at constant speed, and means for driving the same, a second element driven at variable speeds, and means for drivin the same connected to the device the spec of which it is desired to determine, a third element con-- centric with the first element, gearing between said second and third elements whereby the speed of said third element may be varied, and means in connection with said elements comprising pointers which move in adjacent planes for indicating the speed of the device the speed of which it is desired to determine.

6. In a speed indicator, a shaft driven at constant speed, and means for driving the same, a pointer thereon, a friction gear, a second pointer in a planeadjacent the plane of the first-named pointer, means connecting said second pointer to said gear, a second shaft driven at variable speed by the device whose speed is to be determined, a friction Wheel mounted on said second shaft and engaging the face of said friction gear, an indicating pointer mounted in a plane parallel and adjacent to the plane of the first named pointers, means for moving the friction wheel to vary the speed of said friction gear,'and means connecting the indicating pointer with said means for moving the friction wheel for the purpose of indicating the speed of said second shaft.

7. In a speed indicator, a shaft driven at speed is to be determined, a friction wheel carried by said third shaft and engaging the face of said friction gear, means for yieldingly pressing said friction gear and said friction wheel together, means for moving said friction wheel to vary the speed of said friction gear, and means for indicating the extent of such movement.

8. In a speed indicator, a shaft driven at constant speed, means for driving the same, a pointer thereon, a friction gear, a second pointer in a position to be viewed simultaneously with the first-named pointer, means connecting said second pointer to said gear, a second shaft driven at variable speed by the device Whose speed is to be determined,

a friction wheel mounted on said second shaft and engaging the face of said friction gear, an indicating pointer, means for moving the friction Wheel to vary the speed of said friction gear, and means connecting the indicatin moving the riction wheel for the purpose of indicating the speed of said second shaft.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

FRANK W. WOOD.

Witnesses:

HARRY S. GRIFFITH, ROBERT L. EASSON.

pointer with said means for 

